Question

$\mathbf{CuS}\mathbf{O}_{\mathbf{4}}$ reacts with KCN solution and forms:

• A. $K_{3}\lbrack Cu(CN)_{4}\rbrack$
• B. $Cu(CN)$
• C. $Cu(CN)_{2}$
• D. $K_{4}\lbrack Cu(CN)_{6}\rbrack$

Answer 1

Answer: (A)

$K_{3}\lbrack Cu(CN)_{4}\rbrack$

Answer 2

$CuSO_{4}$ on reaction with $KCN$ gives $K_{3}\lbrack Cu(CN)_{4}\rbrack$

$2CuSO_{4} + 10KCN \rightarrow 2K_{3}\lbrack Cu(CN)_{4}\rbrack + 2K_{2}SO_{4} + (CN)_{2}$